Date of Submission
8-2024
Document Type
Thesis
Degree Name
Master of Science in Cellular and Molecular Biology
Department
Biology and Environmental Sciences
Advisor
Eva Sapi, Ph.D.
Committee Member
Alireza G. Senejani, Ph.D.
Committee Member
Nikolas Stasulli, Ph.D.
Keywords
Breast Cancer, Borrelia burgdorferi, Lyme Disease, Inflammatory Markers, Outer Membrane Vesicles (OMVs)
MeSH
Breast Neoplasms, Borrelia burgdorferi, Lyme Disease
LCSH
Breast--Cancer--Research, Borrelia burgdorferi, Lyme disease
Abstract
Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer-related death among women. Emerging studies have reported that infections by microorganisms, including bacterial spirochetes like Borrelia burgdorferi, are associated with breast cancer and correspond to poor prognosis. Previous research by the Lyme disease research lab has demonstrated B. burgdorferi’s ability to infect MDA-MB-231 breast cancer cells and alter their tumorigenic properties. Similar cellular changes were observed in neuronal cells infected with B. burgdorferi or co-cultured with outer membrane vesicles (OMVs) isolated from this pathogen. The OMVs released from B. burgdorferi have been observed to possibly contain virulence factors that may have a role in B. burgdorferi infection in human cells. These OMVs, potentially carrying virulence factors, prompted this study to investigate whether B. burgdorferi OMVs can induce the expression of inflammatory and/or tissue remodeling genes in breast cancer cells similar to those caused by direct spirochete infection.
This study explored various methods for isolating B. burgdorferi OMVs, including the ExoBacteriaTM kit method and qEV size-exclusion column chromatography. The Bb-OMVs were characterized through transmission electron microscopy and OMV-specific markers like the outer surface membrane proteins OspA and OspC were detected. The analysis of 16S rDNA expression to prove the purity of the Bb-OMVs samples yielded interesting results, demonstrating that the ExoBacteriaTM kit was superior to the alternative isolation method we tested. Further, the effects of OMV co-culture with spirochete infection were compared on the expression of previously studied cancer-associated genes (CXCL8, CXCL10, CCL20, PTGS2) and tissue remodeling markers (MMP1, MMP9, TIMP1, TIMP2) in MDA-MB-231 breast cancer cells using RT-qPCR. The cancer-associated inflammatory markers were reported to have lower levels of expression in Bb-OMV co-cultured cells compared to the direct infection of B. burgdorferi in MDA-MB-231 cells. Lastly, similar reduced expression levels of tissue remodeling markers, MMPs and TIMPs were observed in Bb-OMV co-cultured MDA-MB-231 cells.
Our results in this study suggest that Bb-OMVs can enhance the expression of inflammatory and tumorigenic factors in breast cancer cells, providing insights into the hostpathogen relationship and the potential role of B. burgdorferi in breast cancer development.
Recommended Citation
Jathan, Jasmine Avinash, "Effect of Borrelia burgdorferi Outer Membrane Vesicles on Inflammatory Markers of Breast Cancer Cells" (2024). Master's Theses. 211.
https://digitalcommons.newhaven.edu/masterstheses/211